CoalescingMergeTree collapses sparse updates for faster ClickHouse queries
ClickHouse 25.6 adds CoalescingMergeTree, a new engine that merges sparse updates over time, keeping only the latest version of each entity. This reduces row count and speeds up queries, especially for use‑cases like IoT or vehicle telemetry. The recommended workflow is ingest into a regular MergeTree and serve queries from CoalescingMergeTree.